The only rookie on a Factory bike will be former Moto3 champion and multiple Moto2 race winner Maverick Vinales, who has signed for the returning Suzuki team.

Fellow 20-year-old Jack Miller is jumping straight from Moto3 to the premier-class, where he will ride an Open class Honda for LCR. Having skipped the Moto2 category, how quickly Miller adapts to MotoGP will be seen by many as a sign of Moto2's relevance.

Two World Superbike stars making the crossover will be Eugene Laverty and Loris Baz.

28-year-old Laverty has won races for three different WSBK manufacturers and is a former title runner-up. Like Miller, the Irishman will race the new Open Honda, having signed to ride alongside Nicky Hayden at Aspar.

Baz is just 21 and also a former WSBK race winner. The Frenchman is joining Forward Yamaha, which won the Open class with Aleix Espargaro this season.Scott Redding and Cal Crutchlow on satellite HondasIt was touch and go for a while, but after doing better than anyone else on this year's underpowered RCV1000R during his rookie MotoGP season, Scott Redding has secured a Factory RC213V for 2015.

While the RC213V/Seamless/Brembo/Ohlins package is proven, the 21-year-old is joining a team making its premier-class debut: Marc VDS. Actually Redding is re-joining the team, having raced for Marc VDS during four seasons in Moto2, but the new team members hired for the MotoGP project will need time to gel.

Meanwhile, nothing seems to fire Cal Crutchlow up more than being written off or perceived as the underdog, as proven by his past performances while injured or when overlooked for the latest Ducati parts at the end of 2014.

Dropping back from Factory to Satellite status, Crutchlow will again be out to make the critics swallow their words during his debut season on LCR's Honda RC213V.How much better will Marc Marquez and Valentino Rossi be?Marc Marquez and Valentino Rossi, the top two riders of 2014, both have good reason to believe they will come back stronger in 2015.

Reigning double world champion Marquez missed most of last year's winter tests due to injury and at just 22 years old is yet to reach the peak of his powers. Meanwhile 36-year-old Rossi is confident that his second year with crew chief Silvano Galbusera will bring further gains. The Italian also expects Yamaha to debut a seamless downshift system to match that of Honda.How good will the new Open Honda be?This year's Open class Honda was a disappointment. While the equivalent Forward Yamaha took a podium (and pole) in the hands of Aleix Espargaro, the RCV1000R managed a best race result of seventh, despite being raced by the likes of former world champion Nicky Hayden and Moto2 title runner-up Scott Redding.

Honda management had painted a very different impression about the potential of the bike, most notably a 0.3s per lap difference to the Factory model, which falsely raised expectations among fans, teams and the riders themselves.

Fortunately the Open Honda will be revamped for 2015, most notably through use of this year's (pneumatic valve) RC213V engine. The RC213V-RS, as it will be officially known, won't have the seamless gearbox of the Factory class bike and must run the Open ECU.

However the bike will still enjoy perks such as extra race fuel and the softer Open class rear tyre allocation, meaning it should be firmly in contention for top Open honours at the very least.What can newcomers Suzuki and Aprilia achieve?Suzuki and Aprilia are both returning to MotoGP next season, when they will race under the same Factory 2 rules as Ducati, meaning access to the full range of Open class technical concessions.

If post-season testing was anything to go by, Suzuki should begin somewhere around the tail end of the top ten and must get a grip on the engine reliability issues that dogged Randy de Puniet's wild-card appearance.

Aprilia's progress from the tail of the field will depend on the speed with which they upgrade the former CRT-class ART, with an all-new bike set to debut in 2016.

Both manufacturers have secured a talented rider line-up, with CRT and Open class winner Aleix Espargaro being partnered by rookie Moto2 star Vinales at Suzuki. Aprilia have recalled former MotoGP title runner-up Marco Melandri from WSBK to race alongside podium finisher Alvaro Bautista.

Unlike Honda, Yamaha and Ducati, both 'new' manufacturers will be allowed to develop their electronic software until the end of the 2015 season.Rule changes...2016 will see a major change in the MotoGP rules with the present three classes (Factory, Factory 2 and Open) replaced by a single set of technical regulations, including a control ECU. There will also be a change from Bridgestone to Michelin tyres (see below).

There are no such dramatic changes for 2015, but the bikes will be 2kg lighter (158kg) and the continuing Factories (Honda, Yamaha and Ducati) will be forced to freeze development of their own bespoke ECU software on July 1, in order to concentrate on creating the new, shared, 2016 system.

The punishment for breaking the engine limit has also been reduced - riders starting the next race from pit lane with a delay of five seconds, rather than the previous ten seconds.